The Morbidity and Mortality Weekly Report (MMWR) series is prepared by the Centers for Disease Control and Prevention (CDC) and the current issue celebrates the 50 years of activity with a special number. The articles included in the special issue are:The Cornerstone of Public Health Practice: Public Health Surveillance, 1961–2011 Evolution of Epidemic Investigations and Field Epidemiology during the MMWR Era at CDC — 1961–2011 Laboratory Contributions to Public Health History of Statistics in Public Health at CDC, 1960–2010: the Rise of Statistical Evidence Changing Methods of NCHS Surveys: 1960–2010 and Beyond Vaccine-Preventable Diseases, Immunizations, and MMWR — 1961–2011 Control of Health-Care–Associated Infections, 1961–2011 AIDS: the Early Years and CDC’s ResponseFifty Years of Progress in Chronic Disease Epidemiology and Control Injury Prevention, Violence Prevention, and Trauma Care: Building the Scientific Base Environmental Health in MMWR — 1961–2010 Occupational Epidemiology and the National Institute for Occupational Safety and Health Trends in Global Health and CDC’s International Role, 1961–2011. Advice to a Modern-Day Rip Van Winkle: Changes in State and Local Public Health Practice